Container closure assembly

ABSTRACT

An assembly comprising a container and a closure. The container has a neck, the neck having an interior surface and an exterior surface, the exterior surface having (a) a thread(s), (b) at least two sets of sloping teeth. The closure has (a) a top wall; (b) a side wall having an interior surface, an exterior surface, an upper portion, and a lower portion; (c) a thread(s) on the interior surface of the side wall; (d) a tamper-indicating band having an interior surface, an exterior surface, an upper edge, and a lower edge, the upper edge of said tamper indicating band attached to the lower portion of the side wall by a plurality of rupturable bridges; and (e) a plurality of tabs attached to the lower edge of the tamper-indicating band, each of the tabs having an interior surface and an exterior surface, the exterior surface of each of the tabs bearing at least one sloping tooth, each of the tabs being foldable to contact the interior surface of the tamper-indicating band, whereby, when folded, the at least one sloping tooth on each tab faces toward the axis of the side wall. When the tabs are folded, the sloping teeth on the tabs of the closure, partially engage with the sloping teeth on the exterior surface of the neck of the container.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention provides an easy to open container/closure assembly, more particularly, an easy to open closure/container assembly having a tamper-indicating feature.

2. Discussion of the Art

Two main types of bottle/closure systems that utilize breakaway bands for indicating tampering are currently commercially available. Both types have certain drawbacks. The first type locks the tamper-indicating band in place. The locking mechanism requires the force to remove the cap and to break the band to be applied simultaneously, thereby resulting in high removal torques and high standard deviations of removal torque. The lowest removal torque that can be achieved with this system is approximately 18 inch pounds on average. This force is too high for elderly users and users suffering from arthritis. The second type involves the separation of the opening force from the force required to remove the tamper-indicating band, by allowing approximately 180° of free rotation of the cap before breakage of the band is initiated. Accordingly, the closure is subject to back-off and possible leakage during distribution. This type of closure also does not provide any audible feedback in the area between cap opening and band breakage to reassure the consumer of safety.

U.S. Pat. No. 4,991,731 describes problems encountered when packaging consumable products in sealed containers. These problems are described below.

Due to concerns about material cost, container weight, and breakage, suppliers of consumable products desire to manufacture the container from a plastic substance, such as polypropylene, which is relatively inexpensive and may be colored or translucent. A problem arises when attempting to provide a cap for a plastic container, wherein the cap maintains a hermetic seal. Because it is difficult to maintain a hermetic seal in a plastic container, and conventional metal caps and plastic containers expand by a dissimilar amount, metal caps, by themselves, do not maintain a hermetic seals consistently on plastic containers when subjected to retort conditions.

During retort conditions, heat causes polymer relaxation or shrinkage, especially in the upper neck portion of the container. Injection or extrusion molded plastic bottles are formed by melting and pressure forming, which create stress and memory in the molecules of the polymer. The introduction of heat during the retort process causes those molecules to relax, so as to actually shrink the diameter of the neck portion of the container. This shrinkage causes severe problems in maintaining a conventional metal cap on a plastic bottle. This shrinkage may also prevent the use of a conventional plastic cap with a plastic bottle.

The problems mentioned above can be overcome by applying a substantial amount of torque when initially capping the bottle. However, the amount of torque necessary to maintain a conventional cap on a plastic bottle is so high that a person would not be able to easily twist the cap off the bottle following retort. Other alternatives would be to use an extremely expensive plastic to fabricate the bottle so that the plastic would not shrink at retort temperatures and could maintain an internal vacuum without distortion.

Screw on bottle caps have a tendency to loosen from a tightened condition on a threaded bottle neck finish. This tendency to loosen is often referred to as “back off”. This tendency to loosen has a number of causes, including, for example, temperature change, creep in the bottle and cap materials, relaxation of a liner or sealant material, and vibration during handling and shipping. This problem is more frequently encountered when the screw threads have a high pitch to enable the cap to be quickly removed and reinstalled with limited twisting action. Loose caps create problems for the manufacturer and retailer of packaged goods and even for the ultimate user. Loose caps can falsely indicate tampering, and, of course, allow spillage or leakage of the contents as well as entrance of contaminants into the container. A good moisture seal is especially important, for example, when pharmaceuticals and dietary supplements can be adversely affected by excess increases of or by excess decreases of moisture content. While “anti-back off” features are known in the industry, these features have not generally been available for bottles intended for use by elderly persons having limited strength and by sufferers from arthritis.

U.S. Pat. No. 6,296130, EP 0 864 504 A1, WO 01/15988 A1, U.S. Patent Application Publication 2003/0160020 A1, and U.S. Pat. No. 4,349,116 disclose closure/container assemblies having “anti-back off” features. It is apparent that there is a need for an improved container/closure assembly that provides system seal integrity during retort, as well as permitting the sanitary opening of the container in a single action motion with a very low removal torque.

SUMMARY OF THE INVENTION

This invention provides a closure that addresses the aforedescribed disadvantages of container/closure systems that are currently commercially available. In one embodiment, the closure comprises:

(a) a top wall;

(b) a side wall having an interior surface, an exterior surface, an upper portion, and a lower portion;

(c) a thread(s) on the interior surface of the side wall;

(d) a tamper-indicating band having an interior surface, an exterior surface, an upper edge, and a lower edge, the upper edge of the tamper-indicating band attached to the lower portion of the side wall by a plurality of rupturable bridges; and

(e) a plurality of tabs attached to the lower edge of the tamper-indicating band, each of the tabs having an interior surface and an exterior surface, the exterior surface of each of the tabs bearing at least one sloping tooth, each of the tabs being foldable to contact the interior surface of the tamper-indicating band, whereby, when folded, the at least one sloping tooth on each tab faces toward the axis of the side wall.

The sloping teeth of the closure partially engage at least one set of sloping teeth on the neck of a container. In order to reduce removal torque to the degree desired, it is preferred that all of the teeth in all of the sets of teeth on the neck of the container be offset from the teeth of the closure with which they are partially engaged. However, if all of the teeth in all of the sets of teeth on the neck of the container are offset from the teeth of the closure with which they are partially engaged, the risk of back off increases. Accordingly, it is preferred that at least one, but not all, of the teeth in each set of teeth on the neck of the container be completely engaged with a tooth on the closure, so that removal torque is reduced from the situation in which all of the teeth in each set of teeth on the neck of the container are engaged, while anti-back off features are still retained. The partially engaged sloping teeth on the closure and the partially engaged sloping teeth of the at least one set of sloping teeth on the neck of the container provide a slight drag, i.e., resistance to rotation of the cap, and audible feedback to the user when the closure is rotated to open the container. The partially engaged sloping teeth on the closure and the partially engaged sloping teeth of the at least one set of sloping teeth on the neck of the container also function as an anti-back off feature during manufacturing and distribution of the product contained within the container.

A continuous retaining bead on the container located slightly above the sloping teeth of the closure is also included. As removal torque is applied to the closure, the closure rides upward on the thread(s) on the neck of the container while the sloping teeth on the closure are grabbed under this bead, thereby bringing about a gradual stretching of the rupturable bridges and subsequent breakage of the rupturable bridges to separate the tamper-indicating band from the side wall of the closure. The closure/container assembly described herein can provide removal torques between approximately 3 and 16 inch pounds on average, thereby enabling elderly users and arthritic users to open the container with ease.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view in elevation of an embodiment of the closure described herein.

FIG. 2 is a top plan view of the closure of FIG. 1. In this figure, the tabs are not folded so as to be encircled by the tamper-indicating band.

FIG. 3A is a bottom plan view of the closure of FIG. 1. In this figure, the tabs are not folded so as to be encircled by the tamper-indicating band.

FIG. 3B is an enlarged view of area 3B of FIG. 3A. In this figure, the tabs are not folded so as to be encircled by the tamper-indicating band.

FIG. 3C is an enlarged view of area 3B of FIG. 3A. In this figure, the tabs are folded so as to be encircled by the tamper-indicating band.

FIG. 4 is an exploded side view in elevation of the closure of FIG. 1 and a container that receives the closure.

FIG. 5 is a side view in elevation of the assembly of the closure and the container of FIG. 4.

FIG. 6 is a cross-sectional view, greatly enlarged, taken along line 6-6 of FIG. 5.

FIG. 7 is a cross-sectional view, greatly enlarged, taken along line 7-7 of FIG. 5.

FIG. 8 is a top plan view of the neck of the container shown in FIG. 4.

DETAILED DESCRIPTION

As used herein term “side wall” means that portion of a closure depending from the top wall of the closure. The term “side wall” is synonymous with the term “skirt.” As used herein, the expression “top wall” means a panel that covers the opening of the closure that is positioned distally from the neck of the container. The expression “top wall” is synonymous with the expressions “end wall”, “cover”, “end panel”, “upper portion”. As used herein, the term “tooth” means a projecting part resembling a tooth, as on a saw. The expression “sloping tooth” is synonymous with the term “ratchet.” As used herein, the expression “closure/container assembly” means a combination of the closure and the container to make a completed product. As used herein, the term “closure” means an object that closes the mouth of a container. As used herein, the term “container” means a receptacle for holding or carrying a material. As used herein, the term “etc.” is indicative of a situation in which components similar to components previously listed may be present. For example, if three like components are listed, the term “etc.” indicates that there may be four or more similar components actually being referred to. The expressions “removal force” and “removal torque” are used interchangeably. As used herein, the expression “axis of the side wall” means a straight line about which the side wall is designed to rotate. The term “thread(s)” is intended to mean one or more threads.

Referring now to FIGS. 1-7, inclusive, a closure 10 comprises a top wall 12, a side wall 14, preferably cylindrical in shape, having an upper end 16 and a lower end 18. Attached to the lower end 18 is a tamper-indicating band 20, preferably cylindrical in shape, having an exterior major surface 22, preferably cylindrical in shape, an interior major surface 24, preferably cylindrical in shape, an upper edge 26, and a lower edge 28. Projecting from the upper edge 26 of the tamper-indicating band 20 is a series of rupturable bridges 30 a, 30 b, 30 c, etc. These rupturable bridges 30 a, 30 b, 30 c, etc., connect the tamper-indicating band 20 to the lower end 18 of the side wall 14 of the closure 10. The rupturable bridges 30 a, 30 b, 30 c, etc., must be broken or ruptured to cause the tamper-indicating band 20 to separate from the side wall 14 to provide an indication of the opening of the container. Rupturable bridges 30 a, 30 b, 30 c, etc., are described, for example, in U.S. Pat. No. 4,981,230, incorporated herein by reference. Between the rupturable bridges 30 a, 30 b, 30 c, etc., are openings 32 a, 32 b, 32 c, etc. The purpose of the rupturable bridges 30 a, 30 b, 30 c, etc., is to attach the tamper-indicating band 20 to the lower end 18 of the side wall 14. The purpose of the openings 32 a, 32 b, 32 c, etc., is to provide sufficient separation between the rupturable bridges 30 a, 30 b, 30 c, etc., to enable the rupturable bridges 30 a, 30 b, 30 c, etc., to be broken by a removal torque that can be generated by an elderly or arthritic user. The number of rupturable bridges 30 a, 30 b, 30 c, etc., formed around the circumference of the closure typically ranges from about five (5) to about fifteen (15). If the rupturable bridges 30 a, 30 b, 30 c, etc., are too narrow, they will be broken during production. If the rupturable bridges 30 a, 30 b, 30 c, etc., are too wide, the closure cannot be removed from the neck of the container without application of a significant amount of torque. For example, the rupturable bridges can range from about 0.003 inch to about 0.050 inch in thickness.

Projecting from the lower edge 28 of the tamper-indicating band 20 is a series of tabs 34 a, 34 b, 34 c, etc. These tabs 34 a, 34 b, 34 c, etc. are substantially rectangular in shape. For the sake of simplification, tab 34 a will be described in detail. However, it should be noted that tabs 34 b, 34 c, etc., are substantially identical to tab 34 a. Tab 34 a has an interior major surface 36 a and an exterior major surface 38 a. On the exterior major surface 38 a of tab 34 a is formed at least one sloping tooth 40 a. Typically, the aforementioned exterior major surface 38 a of tab 34 a contains two or more sloping teeth 40 a and 40 b. Tab 34 a is attached to the lower edge 28 of the tamper-indicating band 20 by a living hinge 42 a. The living hinge 42 a is designed so as to enable the tab 34 a to be folded, whereby the interior major surface 36 a of the tab 34 a, i.e., the major surface not bearing the sloping tooth 40 a or teeth 40 a and 40 b is flush against the interior major surface 24 of the tamper-indicating band 20, and the exterior major surface 38 a of the tab 34 a, i.e., the major surface bearing the sloping teeth 40 a and 40 b faces away from the tamper-indicating band 20 and toward the axis of the side wall 14. Between each set of adjacent tabs, e.g., 34 a and 34 b, or 34 b and 34 c, etc., is a connecting bridge 44. The purpose of the connecting bridges 44 is to enable all of the tabs 34 a, 34 b, 34 c, etc., to be simultaneously folded up so as to contact the interior major surface 24 of the tamper-indicating band 20. In addition, the connecting bridges 44 maintain proper alignment between adjacent tabs 34 a, 34 b, 34 c, etc., so that consistent performance and consistent opening force is provided during the operation of removing the closure 10 from the neck of the container. There is a gap between each connecting bridge 44 and the lower edge 28 of the tamper-indicating band 20 to enable to living hinges 42 a to function with a low level of resistance to folding. The width of the connecting bridges 44 should be sufficiently low in order to reduce the force required to open the container. For example, the width of the connecting bridge 44 can be as low as 0.003 inch. However, the width of the connecting bridges 44 must be sufficient in order to maintain adequate strength during the operations of filling the container and applying the closure 10 to the container. For example, the width of the connecting bridge 44 can be as high as 0.10 inch. Tabs 34 a, 34 b, 34 c, etc., and connecting bridges 44 are described, for example, in U.S. Pat. No. 4,981,230, previously incorporated herein by reference.

The side wall 14 has an interior major surface 46 and an exterior major surface 48. In the interior major surface 46 of the side wall 14 positioned near the upper end 16 of the side wall 14 is a groove (not shown). This groove (not shown) receives a disk 52 having an interior major surface 54 and an exterior major surface 56, which disk 52 forms the top of the closure 10. The groove (not shown) is sufficiently wide so that the disk 52 can be rotated therein. At the peripheral edge of the inner major surface 54 of the disk is a layer 58 of oxygen-impervious, moisture-impervious polymeric material, which functions as a gasket or seal. The interior major surface 46 of the side wall 14 contains thread(s) 60, which mate with thread(s) on the neck of the container, which will be described in detail later.

Referring now to FIGS. 4-8, inclusive, a container 100 suitable for use with the closure 10 described herein typically comprises a body 102 and a neck 104. The neck 104 of the container 100 surrounds the mouth 106 of the container 100. The neck 104 of the container 100 comprises thread(s) 108, which mate with the thread(s) 60 on the interior major surface 46 of the side wall 14 of the closure 10. The start of the thread(s) 108 is designated by the reference numeral 110. Also on the neck 104 of the container 100 are a set 112 a of sloping teeth 114 a, 114 b, 114 c, 114 d and a set 112 b of sloping teeth 116 a, 116 b, 116 c, 116 d. As shown in FIG. 8, only two sets 112 a, 112 b of sloping teeth are shown. However, more sets of sloping teeth can be formed on the neck 104 of the container 100. Sloping teeth 114 a, 114 b, 114 c, 116 a, 116 b, 116 c, 40 a, 40 b are described,.for example, in U.S. Pat. No. 4,813,561, incorporated herein by reference. The neck 104 of the container 100 further comprises a continuous retaining bead 120. The continuous retaining bead 120 is positioned in such a manner as to prevent removal of the tamper-indicating band 20 when the closure 10 is removed from the neck 104 of the container.

Although the sloping teeth 114 a, 114 b, 114 c, 114 d and the sloping teeth 116 a, 116 b, 116 c, and 116 d (and optionally other sets of sloping teeth similar to 114 a, 114 b, 114 c, 114 d, 116 a, 116 b, 116 c, and 116 d on the neck 104 of the container 100) engage the sloping teeth 40 a and 40 b (and optionally other sets of sloping teeth similar to 40 a and 40 b on the closure 10), the sloping teeth on the neck 104 of the container 100 are offset slightly from the sloping teeth on the tabs 34 a, 34 b, 34 c, etc. For example, if each the sloping teeth 114 a, 114 b, 114 c, and 114 d and each of the sloping teeth 116 a, 116 b, 116 c, and 116 d are positioned so that a given tooth is occupies 100 of the circumference of the neck 104 of the container 100, the sloping teeth 40 a and 40 b on the tab 34 a are positioned so that a given tooth 40 a does not occupy 10° or an integral multiple of 10° of the circumference formed by the tabs 34 a, 34 b, 34 c, etc., of the closure 10. In one embodiment, if each of the sloping teeth 114 a, 114 b, 114 c, and 114 d and each of the sloping teeth 116 a, 116 b, 116 c, and 116 d are positioned so that a given tooth occupies 10° of the circumference of the neck 104 of the container 100, a given tooth 40 a on a tab 34 a can occupy, for example, 12.5° of the circumference formed by the tabs 34 a, 34 b, 34 c, etc., of the closure 10. The offset produced by angular spacings is not limited to 10° for sloping teeth 114 a, 114 b, 114 c, and 114 d and sloping teeth 116 a, 116 b, 116 c, and 116 d on the neck 104 of the container 100 and 12.5° for sloping teeth 40 a, 40 b on the circumference formed by the tabs 34 a, 34 b, 34 c, etc., of the closure 10, i.e., 2.5° . The offset can be, for example, any angle between, for example, 1° and 9°. However, the offset cannot be, for example, 0°, 10°, 20°, or 10n°, where n is an integer. Offsetting the sloping teeth 40 a and 40 b on the tabs 34 a, 34 b, 34 c, etc., of the closure 10 from the sloping teeth 114 a, 114 b, 114 c, and 114 d and sloping teeth 116 a, 116 b, 116 c, and 116 d on the neck 104 of the of the container 100 provides at least two advantages:

(a) lower removal torque

(b) greater strength to with stand the forces encountered during production

It should also be noted that any two adjacent sloping teeth, e.g., 114 a, 114 b, on the neck 104 of the container 100 or any two adjacent sloping teeth, e.g., 40 a and 40 b, on a tab 34 a need not abut one another. Adjacent sloping teeth e.g., 114 a, 114 b, on the neck 104 of the container 100 or adjacent sloping teeth on a tab 34 a can be separated by a small angular distance, such as, for example 1° of arc. However, the requirement specified previously for the offset must be adhered to in order to obtain the benefits of the closure described herein.

-   -   L=length of arc on the circumference of the closure in degrees         and length of arc on the circumference of the neck 104 of the         container 100 in degrees     -   n_(tc)=number of teeth in the at least one set of sloping teeth         in the arc L on the closure 10     -   n_(tb)=number of teeth in the at least one set of sloping teeth         in the arc L on the container 100         In order to ensure that the at least one set of teeth on the         closure only partially engages the at least one set of teeth on         the neck 104 of the container 100, it is preferred that n_(tc)         not be equal to equal to n_(tb) and that L/n_(tc) not be equal         to L/n_(tb) As a representative example, if L=50°, then n_(tc)=5         and n_(tb)=4. As can be seen in FIG. 6, the arc L contains five         teeth 40 a, 40 b, 40 a, 40 b, and 40 a of the closure and four         teeth 116 a, 116 b, 116 c, and 116 d of the container 100.

In order to reduce removal torque to the degree desired, it is preferred that all of the teeth in all of the sets of teeth on the neck 104 of the container 100 be offset from the teeth of the closure 10 with which they are partially engaged. However, if all of the teeth in all of the sets of teeth on the neck 104 of the container 100 are offset from the teeth of the closure 10 with which they are partially engaged, the risk of “back off” increases. Accordingly, it is preferred that at least one, but not all, of the teeth in each set of teeth on the neck 104 of the container 100 be completely engaged with a tooth on the closure 10, so that removal torque is reduced from the situation in which all of the teeth in each set of teeth on the neck 104 of the container 100 are engaged, while “anti-back off” features are still retained. For example, if the neck 104 of the container 100 contains two sets of teeth positioned 180° apart, and each set of teeth contains four teeth, it is preferred that one of the four teeth in each set of teeth be completely engaged with a tooth on the closure 10 and that the remaining teeth be only partially engaged with the teeth on the closure 10. However, two or three teeth of each set of four teeth on the neck 104 of the container 100 can be completely engaged with teeth on the closure 10. It should be noted that as more teeth of each set of teeth on the neck 104 of the container 100 are engaged with teeth of the closure 10, the amount of force required to remove the closure 10 increases.

The material of the closure 10 can be any polymeric material capable of being molded, cut, folded, and assembled to form the closure 10 described herein. Representative examples of polymeric material suitable for preparing the closure 10 include, but are not limited to, polyolefins, such as, for example, polypropylene and polyethylene. Other polymeric materials, such as, for example, polycarbonate, polyvinyl chloride, polystyrene, polylactic acid, synthetic elastomers, natural latex rubbers, polyesters, such as, for example, polyethylene terephthalate, nylon, and similar materials.

Materials that are suitable for preparing the disk 52 that is inserted in the groove (not shown) in the closure 10 are capable of being formed, stamped, cast, or molded into shapes having specified surface dimensions and thickness dimensions and that exhibit specified flexibility or rigidity. Representative examples of materials suitable for preparing the disk 52 include, but are not limited to, metals, composite materials comprising metal, other composite materials not comprising metal, or polymeric materials comprising a single layer or a plurality of layers laminated together. Representative examples of metals suitable for preparing the disk 52 include, but are not limited to, stainless steel, tin-free steel, aluminum, metal composites containing carbon, and other composite materials. Representative examples of polymeric materials suitable for preparing the disk 52 include, but are not limited to, polyolefins, such as, for example, polypropylene and polyethylene. Other polymeric materials, such as, for example, polycarbonate, polyvinyl chloride, polystyrene, polylactic acid, synthetic elastomers, natural latex rubbers, polyesters, such as, for example, polyethylene terephthalate, nylon, and similar materials.

Properties of metal disks that can be used in the closure of this invention are described, for example, in U.S. Pat. No. 4,991,731, incorporated herein by reference. See column 4, line 53 through column 5, line 24 of U.S. Pat. No. 4,991,731. The disk described in U.S. Pat. No. 4,991,731 further contains a fusible coating on the major surface thereof facing the contents of the container 100. Disks suitable for use herein can also have such a fusible coating on the major surface thereof facing the contents of the container 100 or on both major surfaces thereof. Such fusible coatings for metallic disks include, but are not limited to, epoxy coatings, enamel coatings. Another coating material suitable for composite disks or polymeric disks is ethylene vinyl acetate. It is not required that the disk have a fusible coating on one or both major surfaces thereof.

The gasket 58 that is placed around the peripheral edge of the disk is a polymeric material that is capable of creating a hermetic seal by means of terminal sterilization at a temperature of up to 275° F. Representative examples of polymeric materials suitable for preparing the gasket 58 include, but are not limited to, polymeric materials comprising a single layer or a plurality of layers laminated together, which materials can be formed, stamped, cast, or molded into shapes having specified surface dimensions and thickness dimensions. Representative materials suitable for preparing the gasket 58 include, but are not limited to, polyolefins, such as, for example, polypropylene and polyethylene, polystyrene, polylactic acid, synthetic elastomers, natural latex rubbers, polyesters, such as, for example, polyethylene terephthalate, nylons and other soft to rigid materials modified for a specified value of durometer. U.S. Pat. No. 4,981,230, previously incorporated herein by reference, discloses plastisols for preparing the gasket 58. A typical plastisol is a polyvinyl chloride resin that is applied from a solvent.

The container 100 is preferably made of a polymeric material that is a single layer material or a multiple layer material that can be formed, stamped, cast, or molded into a shape having specified dimensions and specified wall thicknesses. The polymeric material can be either flexible or rigid. Representative example of polymeric material suitable for preparing the container 100 include, but are not limited to, polyolefins, such as, for example, polypropylene and polyethylene, which polyolefins can optionally be blended with ethyl vinyl alcohol, ethylene vinyl acetate, polyvinylidene chloride (saran), Surlyn® resin, Admer® resin, or similar barrier and adhesive layers. Other polymeric materials, such as, for example, polycarbonate, polyvinyl chloride, polystyrene, polylactic acid, synthetic elastomers, natural latex rubbers, polyesters, such as, for example, polyethylene terephthalate, nylon, and similar materials can also be used.

In place of a series of rupturable bridges between the tamper-indicating band and the lower portion of the side wall, a line of weakness can be formed between the tamper-indicating band and the lower portion of the side wall. Upon removal of the closure from the container 100, the tamper-indicating band will separate from the lower portion of the side wall along the line of weakness. The line of weakness and method for forming a line of weakness is described in U.S. Pat. No. 4,813,561, incorporated herein by reference.

A tamper-indicating band 20 can be provided to the lower end 18 of the side wall 14 by means of a mold that has been designed for that purpose. Then, an appropriate blade can be used to form the openings 32 a, 32 b, 32 c, etc., adjacent to the rupturable bridges 30 a, 30 b, 30 c, etc. The blade can be a component of the mold or can be provided separately from the mold. In lieu of the use of rupturable bridges 30 a, 30 b, 30 c, etc., it is suitable, but not preferred, to employ a score line (not shown) to form a weakened region between the tamper-indicating band 20 and the lower end 18 of the side wall 14.

Containers and methods for making thereof are described in U.S. Pat. Nos. 4,349,116; 4,991,731; 5,004,110; and 5,217,737, all of which are incorporated herein by reference.

Conventional closure application machinery can be used to apply the closure 10 to the container 100. Specifically, capping machinery would have grasping elements commonly known as capping chucks to grasp and hold the closure 10 in a position above the neck 104 of the container 100 for placement of the closure 10 onto the neck 104 of the container 100. Prior to applying the closure 10 to the container 100, the tabs 343 a, 34 b, and 34 c, etc., are folded so that the teeth 40 a, 40 b, face the axis of the side wall 14. The capping chucks are driven by a suitable source of energy, and suitable mechanical linkages are utilized to spin the chuck at the appropriate speed to apply the closure 10 to the neck 104 of the container 100. The capping chuck must also have the means for limiting the rotational force and terminating the capping operation once the closure 10 has sealed the container 100 but not advanced so far as to rotate beyond the available thread(s) 108 on the neck 104 of the container 100 or the available thread(s) 60 on the interior major surface 46 of the side wall 14 of the closure 10.

Operation

To open the container 100 described herein, an individual grasps the closure 10 and twists so as to apply sufficient removal torque to the closure 10. On account of the offset of all but at least one of the sloping teeth in the sets of sloping teeth on the neck 104 of the container 100 relative to the sloping teeth on the closure 10, the removal torque can be as low as 3 inch pounds on average, and is typically less than 18 inch pounds on average, more likely less than 16 inch pounds on average. This low level of removal torque renders the assembly of the closure and the container 100 described herein suitable for use by arthritic users and elderly users. The tamper-indicating band 20 assures the user that the assembly of the closure 10 and the container 100 has not been subject to tampering. The rupturable bridges 30 a, 30, 30 c, etc., break in a serial manner, i.e., one after another in order, thereby separating the tamper-indicating band 20 from the lower end 18 of the side wall 14 of the closure 10. As removal torque is applied to the closure 10, the closure 10 rides upward on the threads on the neck 104 of the container 100 while the sloping teeth on the closure are grabbed under the retaining bead 120, thereby bringing about a gradual stretching of the rupturable bridges 30 a, 30 b, 30 c, etc., and subsequent breakage of the rupturable bridges 30 a, 30 b, 30 c, etc., to separate the tamper-indicating band 20 from the lower end 18 of the side wall 14 of the closure 10. The retaining bead 120 enables the container 100 to retain the tamper-indicating band 20 on the neck 104 of the container 100.

The threads on the container 100 and the threads on the closure 10 can have the shape shown in FIGS. 4 and 7, in which the bottom of the thread(s) 108 of the neck 104 of the container 100 and the top of the thread(s) 60 of the closure 10 are made relatively flat and horizontal. The result is that any relative movement between the thread(s) 60 and the thread(s) 108 during a retorting operation caused by the unequal expansion of the closure 10 and the container 100 causes an insignificant relative vertical movement between the thread(s) 60 and the thread(s) 108 so that the threads retain their vertical tension for both heated and cooled packages. Threads for closures and containers are described in further detail in U.S. Pat. No. 4,813,561, incorporated herein by reference.

This invention allows the removal torque of a closure to be controlled at a low level, such as, for example less than 16 inch pounds on average. The invention also allows an audible feature as the closure is being rotated. This closure is particularly useful for both elderly and arthritic patients.

The closure/container assembly described herein can be utilized in any closure/container assembly intended to be used by either elderly or arthritic patients.

Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein. 

1. An assembly comprising a container and a closure, said container having a neck, said neck having an interior surface and an exterior surface, said exterior surface having (a) a thread(s), (b) at least two sets of sloping teeth, said closure having (a) a top wall; (b) a side wall having an interior surface, an exterior surface, an upper portion, and a lower portion; (c) a thread(s) on the interior surface of said side wall; (d) a tamper-indicating band having an interior surface, an exterior surface, an upper edge, and a lower edge, the upper edge of said tamper indicating band attached to the lower portion of said side wall by a plurality of rupturable bridges; and (e) a plurality of tabs attached to the lower edge of the tamper-indicating band, each of the tabs having an interior surface and an exterior surface, the exterior surface of each of the tabs bearing at least one sloping tooth, each of the tabs being foldable to contact the interior surface of the tamper-indicating band, whereby, when folded, the at least one sloping tooth on each tab faces toward the axis of the side wall, wherein the sloping teeth on the tabs of the closure, when the tabs are folded, partially engage with sloping teeth on the exterior surface of the neck of the container.
 2. The assembly of claim 1, wherein the sloping teeth on the exterior surface of the neck of the container are offset from the sloping teeth on the tabs of the closure to a sufficient degree that the sloping teeth on the tabs of the closure do not lock with the sloping teeth on the exterior surface of the neck of the container, thereby enabling the closure to be rotated about the neck of the container.
 3. The assembly of claim 1, wherein said thread(s) are inclined sufficiently to enable rotation of the closure to bring about serial rupture of the rupturable bridges of the closure.
 4. The assembly of claim 1, wherein said neck of said container contains two sets of sloping teeth.
 5. The assembly of claim 1, wherein each set of sloping teeth comprises at least two teeth.
 6. The assembly of claim 1, further including a connecting bridge between two adjacent tabs.
 7. The closure of claim 1, wherein each tab bears a plurality of sloping teeth on the exterior surface thereof.
 8. The closure of claim 1, further having a groove formed in the interior surface of said side wall.
 9. The closure of claim 4, wherein a disk is included in said groove. 